The publications and other materials used herein to illuminate the background of the invention, and in particular, the cases to provide additional details respecting the practice, are incorporated by reference.
Intrauterine systems (IUS) are well known in the art. For example, document GB 1 568 419 presents an intrauterine device that has a T-shaped frame. The arms of the frame are curved so that they will resist becoming embedded in the sidewalls of the fundus and the arms will flex under uterine contractions. In its preferred and only illustrated form, the device includes a formation adapted to resist movement into the cervical canal, said formation having the form of a pair of lugs extending away from the stem of the device.
Document U.S. Pat. No. 4,578,076 by the Applicant discloses intrauterine and intracervical devices that also have a T-shaped frame. The frame has a vertical stem portion with a rounded knob at the top of the vertical stem and two flat flexible downward slanting arms extending from the knob, the arms tapering from the knob to the ends of the arms and having a downward bend of about 45°-110° proximate the end of each arm. Furthermore, the arms slant down from the knob at an angle of about 10°-25°, when measured from the horizontal, i.e. the plane perpendicular to the longitudinal axis of the elongate member.
The problem that is addressed in these documents is the irritation of the endometrium and bleeding caused by the devices, which have the traditional T-shape, i.e. those in which the arms are not bent down towards the other end of the elongate member.
Document FR 81 22676 discloses a device that comprises three pairs of transverse members. Only one pair of these members is located at an end of the elongate member. The device also provides a large area of contact with the walls of the uterus, thus creating problems of bleeding and pain for the user. Furthermore, one end of the elongate member is provided with a half sphere having sharp edges. Such a sphere, especially with its sharp edges facilitates the intrusion of the device into the wall of the uterus, thus making the removal of the device highly difficult.